| No | Pattern | Freq | Relations |
|---|---|---|---|
| 1 | [modal v] have been difficult [prep] [art] | 10 |
|
| 2 | [vb mod] have been difficult [prep] [art] | 10 |
|
| 3 | would have been difficult [prep] [art] | 8 |
|
| 4 | would have been difficult [prep] [art] | 8 |
|
| 5 | have been difficult [prep] [art] [noun] | 10 |
|
| 6 | have been difficult [prep] [art] [noun pl] | 5 |
|
| 7 | have been difficult [prep] [art] [noun sg] | 5 |
|
